iprange_ipv6_sub was substracting 2 unsigned ints and then casting
the result to int to find out whether they are lt, eq or gt each
other, this doesn't work if the full 32 bits of each part
can be used in IPv6 addresses. Patch should remedy that without
significant performance penalties. Also number of ntohl
calls can be reduced this way (Jozsef Kadlecsik).
Signed-off-by: NThomas Jacob <jacob@internet24.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>